For me, it's about having a job I enjoy and feel like I'm good at. Which would apply to most of the jobs I've done. So in those circumstances I'd just get a new job, there are lots of roles and industries that interest me.
The problem would occur if I was unemployed and unemployable because my skills (or any new skills I could conceivably learn) were no longer valuable.
I would be really surprised if there was anything more then a fringe minority that found a sense of purpose from their job.